Surfacing of inking rolls



Sept. 12, 1939. w; A. L IPPINCOTT Er Al. 2,172,394

SURFACING OF INKING ROLLS Original Filed NOV, l2, 1954 Qr//e ou i @UHRPatented Sept. l2, 1939 UNITED STATES SURFACING F INKING ROLLS Wells A.Lippincott and Bruce W. Hubbard, Oak

Park, Ill., assignors to Ideal Roller & Manufacturing Company, Chicago,Ill., a corporation of Illinois Application November 12, 1934, SerialNo; 752,647 f Renewed June27, 1938 Claims.

This invention relates to the surfacing ofthe inking rolls for printingpresses with a film of printers composition and has more particularreference to the formation of such a coating by a method wherein theentire roller surface is at one time submerged in a body of thecomposition in a molten state.

The primary object of the invention is to provide a method of the abovecharacter by which a coating of uniform thickness may be formed over theentire roller surface, and rollers may be coated at a comparatively highrate of production.

Another object is to provide for the effective elimination of air cellsin the coating formed on a roller by the above method.

The invention also resides in the novel character of the apparatus forcarrying out the foregoing objects.

Other objects and advantages of the invention will become apparent fromthe following detailed description taken in connection with theaccompanying drawing, in which Figure 1 is an elevational view of anapparatus by which the invention may be practiced.

Fig. 2 is a side elevational view of the apparatus shown in Fig. 1.

Fig. 3 is a fragmentary view partially in section of a part of the drivemechanism shown in Fig. 2.

Fig. 4 is a fragmentary sectional view illustrating a modification.

The invention is susceptible of various modifications and therefore wedo not, by the present exemplary disclosure, intend to limit theinvention, but aim to cover all modifications and alternatives fallingwithin the spirit and scope of the invention as expressed in theappended claims.

Generally stated, the invention contemplates coating or surfacing aninking roller by a method which involves submerging the entire rollersurface in a body of molten printers composition maintained at theproper temperature and subjecting different parts of the surface to saidbody for different lengths of time such as to produce uniform drainingof the excess composition from the roller surface when the roller isremoved, thereby leaving a congealed film of uniform thickness on thesurface. Accordingly, the invention consists in supporting the roller invertical position during the draining of the vexcess of compositiontherefrom and exposing successive longitudinal sections of the rollersurface to the molten composition for progressively increasing intervalsof time beginning at the upper end o1' the roller. During such exposure,the lower 1ongitudinal sections of the surface onto which coolingcomposition drains down from above are heated by the molten compositionto a greater degree than the upper sections onto which there is lessdrainage. As a result of the natural drainage of the excess compositionunder these conditions, the tendency toward the formation of a lm whichincreases in thickness toward the lower end of the roller may beovercome resulting inthe formation of a coated roller of a diametersubstantially uniform throughout its length.

Preferably, though not necessarily.. the improved method involvessupporting the roller to be coated with its axis in upright positionabove a confined body of molten composition maintained at asubstantially constant level during the coating operation, lowering theroller in an endwise direction and at a gradual and uniformly maintainedrate into the composition, withdrawing the roller from thebodyprogressively and at a uniformly maintained rate, and rotating theroller at least during such withdrawal.

One form of apparatus for practicing the method as above setforth isshown in the drawing wherein the numeral 6 indicates a cylindricalheat-insulated tank adapted to conne a body l of molten printerscomposition greater in length and diameter than the rollers to becoated. Preferably, the lower part of the tank is connected through themedium of a pipe 8 and a power driven gear pump 9 with the lower end ofa storage tank lll in which a body ofjcomposition greater than theamount required to fill the tank 6 may be contained. The composition maybe heated by water within a jacket il and maintained at the usualtemperature'of from 140 to 160 degrees Fahrenheit by an electric heaterl2 controlled by a thermostat I3. If, as will be described later, thecoating operation is performed without circulation of the molteny comyposition through the tank .6,` the composition in the latter may bemaintained at the desired temperature by a suitable thermostaticallycontrolled electric heater Il.

Disposed in vertical position alongside of the tank 6 is a standard I6providing a vertical slideway for a carriage I8 which overlies the tankand supports a vertical rotary shafti9 having a coupling socket 20 bywhich the roller 2i to be coated may be suspended in vertical positionfrom one end of its shaft 22. An electric motor 23 mounted on thecarriage is arranged to rotate the roller through appropriate speedreduction gearing 2l and a belt 25 connecting cone pulleys 26 andshiftable into different positions to permit adjustment of the speed ofrotation of the roller.

To provide means for moving the roller inta and out of the tank 6, alead screw 21 extends alongside the upper part of the standard i6 withits opposite ends supported by brackets 28.' Encircling the screw 21 isa nut 29 journaled in bearings 30 supported by the carriage. To enablethe nut to be rotated in opposite directions, suitable reversingmechanismy may be employed.

Ilv

clutch collar I2 which may be shifted into clutchi ing engagement witheither of two beveled gears 3l which are loose on the shaft ll and meshwith a gear 34 driven from the motor .by means such as the belt 35. Theclutch may be shifted by mampulation of a handle 38 operating a yokewhich engages the collar 32. rChanges inthe rate of entry and withdrawalofthe roller may be effected in any desired way. For example, where adirectcurrent motor is used, the speed thereof may be adjusted bychanging the position of a rheostat controller 31 governing the motorcircuit.

For a purpose to more fully appear later, a trough 3B completelysurrounds the upper end of the tank 6 and constitutes'an overflowreceptacle from'which the'excess of composition delivered to the tank 6may be returned to the storage tank I0 through a pipe 39.

Preparatory to a coating operation, the roller to be coated is suspendedfrom the shaft I9.' as shown in Figs.'1 and 2, and after the tank 6 hasbeen filled by operation of the pump 9 and a uniform temperatureattained, the motor. 23 is started and the -clutch lever 36 shifted intoa position to cause lowering of the'. roller. Downvward endwise movementof the roller at a slow and uniform rate continues until the entireroller surface has been submerged. Then the drive mechanism isconditioned for raising the roller at the `desired rate after which theclutch is shifted to initiate -withdrawal of the roller from the tank.

. As the roller rises, the excess of molten composition retained on eachlongitudinal section rising above thelevel of the composition drainsdownwardly onto lower portions of the roller, the excess. compositionnally being returned to the tank.l Itwill be observed that by loweringand raising theroller in the manner above described, the lowerend of theroller surface will be ex-l posed to -the composition for asubstantially longer time interval than the upper end. For this reason,vveach succeeding section toward the upper end of the roller will beexposed, to the heated composition for a shorter time interval andtherefore will become heated to a lesser degrec; But inasmuch as therate of endwise movement is -maintained uniform, the amount of heatimparted to the roller will be changed progressively from one end of theroller to the other. Thus, as the excess of composition on one sectiondrains down onto the section below, the additional heat available at thelatter pointy will be returned to the adhering composition serving tomaintain'the latter at the proper viscosity for insuring continueddraining to the proper degree. As a result, the excess drains off fromthe roller in a manner such-as to leave a film of approximately uniformthickness over the entire surface even though the excess applied to theupper p0rtions of the roller flows down over the lower parts while it iscooling and its viscosity is thereby decreasing.

To produce a film of the desired uniformity in thickness, relativemovement between the roller and the level of the composition in the tank6 should occur at a rate which is suillciently slow to allow for properprogressive heating of the roller surface in the manner above described.With printers composition of the formula ordinarily used and where aconstant level is mainauasa'i' t tained in the tank` B throughout thecoating operation, a coating of the desired uniformity will be produced,for example, when the roller is lowered into and withdrawn from thecomposition at a rate oi' fteen inches per minute. Slower rates may beused and the maximum permissible rate of movement of the roller will ofcourse vary with other factors such as the viscosity of the compositionsed as determined by the proportions of its ingredients and thetemperature at which it is maintained.

The maintenance of a continuous overflow throughout the coatingoperation is advantageous in that the level of the composition in thetank 6 does not vary appreciably in spite of the displacement ofcomposition by the rollers. Thus, a tank 6 of comparatively small volumemay be employed, and the same rate of roller movement usedin coating allsizes of rollers. If a continuous overflow is not maintained, the levelof the composition in the tank will vary according to the relativediameters of the roller and the tank, so that unless an objectionablylarge tank 1' is used, .the relative diameters of the roller and thetank must be considered in determining the maximum permissible rate atwhich the roller is lowered and raised. If, instead of lowering theroller into the composition gradually, it is immersedv quickly, thewithdrawal should preferably be at a correspondingly lower rate in orderto produce proper progressive heating of the` roller surface. y

By maintaining a continuous overflow from the tank 6 while the roller isbeing lowered into andwithdrawn from the body of molten composition, airbubbles or cells are effectually eliminated from the film retained onthe roller surface. This is due to the fact that the composition at thesurface of the body in the tank Vis constantly moving outwardly from theroller surscribed, foam accumulating at any point on the compositionsurface will be carried in difi'erent directions from the roller intothe overflow outlet thereby becoming trapped-in the tank Il.

face. With the overflow arranged as above det By rotating the rollerduring withdrawal thereof from the tank 6, the elimination of air cellsfrom the final coating is materially facilitated. This is because therotating roller' produces a swirling of the composition within the tankresulting in removal of the bubbles trapped on the roller surface by amechanical brushing action of the composition. These and any bubbleswhich might be in the composition as delivered to the tank rise to thesurface of the composition and vare eiectually removed by overflowaction above described. The rate of vrotation of the roller may varyconsiderably. However, it should not be so fast as to agitate the moltencomposition unduly or result in the formation of a wavy surface on thecoating.

If desired, mechanical means may be provided for assisting in theremoval of .air bubbles which may be trapped on the roller surface as itis immersed. This means may take the form of brushes I0 on a carrier liwhich is supported within the tank 6 below the level of the composition.The brushes are spaced to engage and wipe across vthe roller surface asthe rotating roller is lowered into the tank.

' While it is preferred to move the roller into and out of thecomposition within the tank O, it will be apparent that the samerelative movement between the roller and the level of the comenvasesposition may be obtained by flowing the composition from the tank I intothe tank B and then withdrawing the composition at a uniform rate.Flowing of the composition in this manner may be effected by the pump Swhich may be arranged to be driven by a reversible motor so that itsdirection of discharge may be reversed.

We claim as our invention:

1. 'Ihe method of coating an inking roller with the axis of the rollerdisposed in vertical position which comprises maintaining a confinedbody of molten composition, gradually lowering the roller endwise and ata predetermined rate into the composition until the entire surface to becoated has been submerged, gradually withdrawing the roller from saidbody at a uniform rate, and withdrawing molten composition from saidbody during said lowering and supplying molten composition to the bodyduring said withdrawal to maintain the composition in said body at aconstant level.

2. The method of coating an inking roller which comprises supporting theroller with its axis in vertical position, moving the roller and thelevel of a body of molten printers composition relative to each othervertically in a direction to immerse successive longitudinal sections ofthe roller surface and submerge the entire surface, withdrawing saidroller from the composition at a predetermined rate, and continuouslysupplying molten composition to said body at a rate sufficient tomaintain a substantially constant depth thereof during withdrawal of theroller therefrom.

3. Apparatus for coating a roller with printers' composition comprising,in combination, a tank adapted to contain molten composition and havinga depth and diameter greater than the roller surface, means at the upperend of said tank providing for overflowing of the compositionindifferent radial directions, means by which the roller may be loweredinto said tank and withdrawn therefrom at a slow predetermined rate topermit draining of the excess composition, and means for supplyingmolten composition to the tank to maintain a continuous overflow in saiddiiferent directions away from the roller during withdrawal thereof.

4. Apparatus for coating a roller with printers composition comprising,in combination, a tank adapted to contain'molten composition and havinga depth and diameter greater than the roller surface, an overflowreceptacle at the upper end of said tank constructed to induce the flowof the surface composition outwardly in different directions from thecenter of the tank, means byl which the roller may be lowered into saidtank and withdrawn therefrom at a slow predetermined rate to permitdraining of the excess composition, an auxiliary storage tank containingmolten composition and adapted to receive composition from said overflowreceptacle, and means operable during withdrawal of the roller from saidfirst mentioned tank to withdraw composition from below the level lnsaid storage tank and deliver the composition to the rst mentioned tankbelow the level in the latter and in quantities sumcient to maintain aconstant overflow into said receptacle.

5. Apparatus for coating a roller with printers composition comprising,in combination, a tank adapted to contain molten composition and havinga depth and diameter greater than the roller surface, an overflowreceptacle at the upper end of said tank extending substantially aroundthe entire periphery of the tank, means by which the roller may belowered into said tank and withdrawn therefrom at a slow predeterminedvrate to permit draining of the excess composition, and means forsupplying molten composition to the tank to maintain a continuous overowtherefrom during withdrawal of the roller.

6. Apparatus for coating a roller with printers' composition comprising,in combination, means for supporting a roller with its axis disposed inupright position, a recepticle arranged to contain a body of compositionencircling said roller whereby to apply a coating thereto duringrelative vertical movement between the receptacle and roller, means forrotating the roller, and mechanical means positioned to wipe against theroller surface below the level of the composition within said receptaclewhereby to remove air cells trapped on the roller surface.

'7. Apparatus for coating a roller with printers composition comprisingmeans to support the roller with its axis in upright position, areceptacle adapted to contain a body of molten composition in which theroller may be submerged, means for effecting relative movement betweensaid body of composition and said roller in a direction endwise of thelatter, means operable during at least a part of said relative movementto deliver molten composition to said receptacle at a point below thelevel of the composition therein, an overflow outlet for said receptacleoperable during the delivery of composition to the receptacle to inducethe movement of the surface composition in different directions awayfrom the roller surface, and means for effecting relative rotary motionbetween the composition in said receptacle and said roller whereby toremove trapped air cells from the roller surface.

8. 'I'he method of forming a film of printers composition on theperipheral surface of an' inking roller which comprises maintaining aconned body of said composition in a molten state, submerging theperipheral surface of said roller in said molten compositionprogressively from one end to the other, and wiping said surfaceprogressively from one end to the other while the engaged longitudinalportions of the surface are submerged in said body whereby to remove aircells trapped on the surface.

9. The method of forming a film of printers' composition on theperipheral surface of an inking roller which comprises maintaining aconfined body of said composition in a molten state, immersing theperipheral surface of said roller in said molten composition, and wipingeach portion of said peripheral surface while the latter is submerged insaid body whereby to remove air cells trapped on the surface.

10. Apparatus for forming a film of printers composition on theperiphery of an inking roller comprising means for supporting a roller,a receptacle arranged to contain a body of molten composition encirclingsaid roller whereby to apply a coating of the composition to the rollersurface during relative movement of the receptacle and said rolleraxially of the latter, and mechanical means operable during suchrelative movement to wipe against the roller surface submerged in saidcomposition whereby to remove air cells trapped on the roller surface.

WELLS A. LIPPINCOIT. BRUCE W. HUBBARD.

